A Study on Nucleate Boiling Heat Transfer Characteristics of Acetone on Smooth and Indented Surfaces

This article presents the nucleate boiling heat transfer characteristics of acetone at one bar on smooth and enhanced circular stainless steel surfaces (SS 316) of 20 mm diameter for heat flux between 1 and 4 W cm^? 2, which mimic the operating condition of a typical immersion electronic cooling system. The experimental heat transfer coefficient from the smooth surface is validated against Borishanski correlation 1] within acceptable limits of ± 5%. The steel smooth surface is enhanced by providing 100 equally spaced indents of 0.5 mm diameter and 0.05 mm depth. The experimental results indicate that the enhanced surface shows a good shift in the boiling curve and thus, enhancing the nucleate boiling heat transfer at a lesser wall super heat when compared to the smooth surface by around 35% for tested condition. The effect of subcooling on nucleate boiling in enhanced surface reveal that the heat transfer coefficient degrade by 40 to 55% for a sub cooling of 5 to 10 K. The influence of material is studied by a similar enhanced surface made of brass and compared for the same working condition. The brass enhanced surface showed an improved of around 50% against the steel-enhanced surface. Also, the influence of fluid is studied by comparing acetone and n-pentane, which showed that the latter an enhancement in heat transfer coefficient of 50% over the former.